Radio-Frequency Identification (RFID) technology has become widely used in virtually every industry, including transportation, manufacturing, waste management, postal tracking, airline baggage reconciliation, and highway toll management. A typical RFID system includes RFID tags, an RFID reader, and a computing device. The RFID reader includes a transmitter that may provide energy or information to the tags, and a receiver to receive identity and other information from the tags.
The transmitter outputs RF signals through the antenna to create an electromagnetic field that enables the tags to return an RF signal carrying the information. The transmitter makes use of an amplifier to drive the antenna with a modulated output signal. A conventional tag may be an “active” tag that includes an internal power source, or a “passive” tag that is energized by the field. Once energized, the tags communicate using a pre-defined protocol, allowing the RFID reader to receive information from one or more tags. The computing device serves as an information management system by receiving the information from the RFID reader, and performing some action, such as updating a database or sounding an alarm. In addition, the computing device serves as a mechanism for programming data into the tags via the transmitter.